The present invention generally relates to a contact and a connector configured to carry data at high speeds. More specifically, certain embodiments of the present invention relate to a contact for use in various connectors.
Recently, interface connectors have been developed that are capable of satisfying a common specification for multi-source applications, such as in the telecommunications field, data communications applications, storage area networks and the like. The connectors convey data at very high data rates and should satisfy very strict signal quality criteria. The connectors are used in applications that have very demanding space constraints and thus are developed to satisfy various form factor.
These connectors interconnect a variety of components, such as host boards and daughter boards that carry transceiver ASICs and the like. In certain applications, the connector may be a 20 to 70 position pluggable transceiver (PT) connector that carries digital data signals at high data rates, such as 2.5, 5, and 10 Gbps (gigabits per second ) or higher.
However, as data rate increases, the signal performance of the conventional connectors declines. The signal performance may be characterized in terms of jitter, return loss, insertion loss, attenuation, reflectance, signal to noise ratio and the like. The performance of the connector is affected by several factors, one factor of which is the shape and configuration of the contacts that carry the data signals through the connector. Contacts of conventional design have been found to exhibit declining performance characteristics once the data rate reaches and exceeds 5 or 10 Gbps and higher.
FIG. 9 illustrates a conventional contact 310 designed for small form factor pluggable connectors to carry digital signals at a data rate of up to 2.5 Gbps. The contact 310 is held in a housing of a connector 305. The contact 310 includes a contact beam 312 that is joined to one end of a leg portion 320. An opposite end of the leg portion 320 joins a tail portion 332. The contact beam 312 and tail portion 332 define interfaces at which data signals are conveyed to mating contact pads 357 and 355 on a module board 358 and host board 354, respectively. The contact 310 includes a retention stub 322 that holds the contact 310 in place in the connector 305. The retention stub 322 includes a base end formed with the leg portion 320 at an intermediate point along the length of the leg portion 320. The retention stub 322 projects at a right angle from the leg portion 320 with an outer end 324 terminating at a point remote from the contact 310.
The contact 310 exhibits satisfactory performance at data rates of at least 2.5 Gbps. However, when the data rate is increased to near 10 Gbps and higher the retention stub 322 begins functioning as an electrical stub which causes signal degradation, such as increased jitter, insertion loss, return loss and the like.
A need exists for an improved contact configuration that overcomes the problems noted above and experienced heretofore by convention contacts.